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Goodman Furnace 7 flashes: Low flame sense signal

Updated October 2026 · Sourced from Goodman documentation

🛑 Turn it off and call a licensed pro

The furnace keeps running but the flame sensor micro-amp signal has fallen below the specified level. The manual lists a coated or oxidized sensor, a sensor out of position or a lazy flame from improper gas pressure or combustion air.

Is it safe to keep running? No. Turn it off and get it checked. Book a service visit soon. Flame sensor cleaning and gas pressure checks should be done by a licensed technician.

7 flashes at a glance

Code / how it showsMeaningApplies to
7 flashes
Diagnostic LED seen through the blower door window
Low flame sense signalGoodman GMS8 / Amana AMS8 / GDS8 / ADSS8 80% single-stage gas furnaces (older flash-code control)

Check this first

Only steps a homeowner can do safely. Do not open electrical panels or the burner area.

  1. Look outside at the furnace vent and intake pipe ends. Make sure snow, leaves or a nest are not blocking them. Look only, do not touch the pipes.

🛑 Stop and call a licensed pro if

  • Book a service visit soon. Flame sensor cleaning and gas pressure checks should be done by a licensed technician.
  • You smell gas. Leave the house, do not touch switches, and call your gas utility from outside.
  • Flame rollout, limit or pressure switch codes that come back after one reset.
  • Anything involving the control board, gas valve, flame sensor, igniter or venting.
  • A carbon monoxide alarm sounds. Get everyone outside and call 911 or the fire department.

Safe first steps for any Goodman code

  1. Count the LED flashes through the blower door window before you switch anything off. Cutting power can clear the code.
  2. Replace or clean the furnace air filter.
  3. Check the thermostat: correct mode, set above room temperature, and fresh batteries.
  4. Make sure the furnace power switch and breaker are on. If the furnace has locked out, turning the power off and back on once restarts it.
  5. Make sure the gas valve is in the ON position, following the lighting instructions on the furnace label only.
  6. On high-efficiency furnaces, look at the outside vent and intake pipes for snow, ice, leaves or nests (look only, do not take pipes apart).

Source: Goodman GMS8/AMS8/GDS8/ADSS8 80% Single Stage Service Instructions RS6612006 (July 2013), pp.37-39. Codes are series-specific, so your unit's own manual is the final word. Reviewed October 2026.

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Related Goodman codes

1 flash : Ignition lockout (no flame)2 flashes : Pressure switch stuck closed3 flashes : Pressure switch stuck open4 flashes : Open primary or auxiliary limit5 flashes : Flame sensed with no call for heat6 flashes : Open rollout limit8 flashes : Igniter circuit fault or poor groundContinuous flash : Reversed polarity or poor ground (continuous or rapid flash)E0 : Lockout after three failed ignition attemptsE1 : Low-stage pressure switch closed at start of heatingE2 : Low-stage pressure switch circuit openE3 : Primary limit circuit open (furnace overheating)

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